Pore radius. Snapshots include the primary tetramer (pale blue) and pore surface generated from HOLE2 analysis for CLDN15^WT, CLDN15^D55E, and CLDN15^D55N colored orange, purple, and blue, respectively. The binding site at residues 55 (purple) and D64 (yellow) is shown in Licorice representation without hydrogen atoms for each snapshot. The average and standard deviation for pore radius over 140 ns of voltage (−800 mV) simulation for CLDN15^WT (orange), CLDN15^D55E (purple), and CLDN15^D55N (blue). The average Cα positions of negatively charged pore-lining residues D55, D64, E46, E157, and D145 are represented by dotted lines in the pore radius plots.